[Enhancement] Option to re-open browser with all tabs Collapsed

[fung00]

Description: an option to have the tab tree default to fully collapsed whenever the browser is re-opened after being shut down.

Rationale: if you're re-opening a lot of sub-trees, what you want right away is to see just the top headings so you can quickly navigate to whatever you want first.

Note: An option to fully re-create the previous tree state, with sections expanded or collapsed as when the browser was closed, would be nice too, but much less important (and probably much more work).

BTW: Love Tree Style Tab, could NOT use Firefox (or Waterfox) without it. Brilliant work, many thanks!